BEIRUT (AP) — For Syria's banned Muslim Brotherhood, the uprising against President Bashar Assad that erupted amid Arab Spring revolts in 2011 provided a long-sought opportunity to stage a comeback after decades spent in exile.

Thirty years earlier, the group's own violent uprising against Assad's father, the late Hafez Assad, was brutally crushed, culminating in an infamous massacre in the city of Hama that ended with the group's leadership killed, imprisoned or exiled.

Amid the chaos of the current revolt, the group quickly emerged as the best organized of Assad's political opponents, and is playing an increasingly active role on the ground by providing assistance to military brigades it supports.

It faces enormous challenges in the months ahead, however.

The downfall of the Brotherhood in Egypt has shaken its Syrian counterpart and deepened distrust of the secretive movement by other Syrians who are suspicious of its religious agenda.

Inside Syria, the group faces an uphill battle trying to rebuild its base with the young revolutionaries of today, many of whom view its leadership as aging and out of touch after years away from the country. Moreover, the self-described moderate Islamic group faces fierce competition from better equipped hard-line Salafi fighters and al-Qaida extremists who have emerged as a major force among the ranks of the rebels.

"Despite its rich history of involvement in Syrian politics, for some, the Brotherhood continues to be viewed as a foreign entity merely representing a local branch of the Egyptian movement," said Raphael Lefevre, a visiting fellow at the Carnegie Middle East Center and author of the book "Ashes of Hama: The Muslim Brotherhood in Syria."

"To win hearts and minds, the Syrian group needs to move more decisively to define itself in the context of its own considerable history," he said.

Leaders of the Syrian Brotherhood and activists inside Syria say the group has been actively working in that direction. In addition to its pivotal role in shaping and influencing the opposition abroad, it has stepped up relief assistance to rebel-held areas inside the country and its leaders have made several trips to opposition areas in the north in an attempt to reconnect with residents in Idlib and Aleppo provinces, once considered strongholds of the group.

In February, the group launched al-Ahed, a newspaper which now distributes 10,000 copies bi-weekly in opposition territory. Sheik Hatem al-Tabshi, head of the Brotherhood's Shura Council, preaches in the city of Maarat al-Numan and is seen in videos holding meetings with fighters in the area.

Most significantly, an umbrella group of brigades known as the "Shields of the Revolution" has emerged as a military force closely affiliated with the group, although Brotherhood officials deny any formal ties. Activists, however, say the group is preparing to formally launch its military branch in the country.

"It is not easy to reconnect and restore our presence after 30 years of absence," acknowledged Omar Mushaweh, who heads the group's media communications department. "It requires time, but we have a strong history in Syria and we will get there despite the smear campaign against us," he told The Associated Press from his base in Turkey.

It is precisely this controversial and violent history, however, which makes many Syrians wary of the group. Suspicions that the Brotherhood is ultimately looking to grab power in Syria were fueled by the rapid downfall of the Brotherhood in Egypt when that country's military overthrew former President Mohammed Morsi.

While the Egyptian and Syrian groups share the same name and ideology, they have no organizational ties to speak of. Although modeled after the Egyptian Brotherhood, the Syrian branch took its own path soon after its founding by Mustafa al-Sibai in 1942.

Its Islamist ideology soon clashed with the secular ideology of the ruling Baath party, which outlawed the group in the early 1960s, putting the two sides on a collision course.

In 1982, following years of insurgency during which the Brotherhood and its affiliates carried out bombings and assassinations of government officials, Syrian President Hafez Assad launched a withering assault on the rebellious city of Hama, stronghold of the Brotherhood at the time, leveling entire neighborhoods and killing thousands in one of the most notorious massacres in the modern Middle East.

Amnesty International has estimated that between 10,000 and 25,000 people were killed in the massacre, though conflicting figures exist and the Syrian government has never given an official tally.

The movement's remaining leaders went underground while the rest were killed, imprisoned or exiled and their relatives chased down for years. In successive years, the word "Hama" and "Brotherhood" would be mentioned only in whispers among Syrians.

"There isn't a citizen in Syria, young or old, who doesn't carry with him tragic memories from the '80s which touched the lives of most Syrian families," said Ali Sadr el-Din Bayanouni, a London-based senior member and former leader of the group.

"The same police state that was in the 80s is still ruling Syria now and it is the same desire for change and revolution that triggered the uprising this time around," he said.

Today, the Hama massacre stands as a rallying cry both for those trying to topple the regime, and for Assad, who has seized on the Brotherhood's violent past to try and portray the current popular revolt as an extension of the government's longstanding fight against Islamists.

"We have been fighting the Muslim Brotherhood since the 1950s and we are still fighting them," Assad said in an interview in Oct. 2011. Last month, he praised the massive protests that toppled Morsi, calling his ouster the end of "political Islam."

For Assad's opponents, memories of Hama appeared to be a mobilizing factor early on in the uprising, though many now say they resent what they see as the group's heavy use of money as a key lever of influence.

Last year, activists in Hama commemorated the anniversary of the massacre, throwing red dye into the ancient water wheels on the Orontes River, the city's most famous landmarks.

"Hafez died, and Hama didn't. Bashar will die, and Hama won't," they sprayed on its stone walls.

Still, the Brotherhood faces widespread accusations that it seeks to impose its will on the rest of the opposition, mainly through the Western-backed Syrian National Coalition umbrella bloc. The fundamentalist group has a powerful donor network among members in exile and supporters in oil-rich Gulf countries, especially Qatar.

Tensions within the opposition peaked in March, with critics claiming the Brotherhood orchestrated the election of Ghassan Hitto, a little-known figure, as interim prime minister for the opposition.

About a dozen members of the Coalition suspended their membership a day after Hitto was elected, prompting the Brotherhood's general leader, Mohammad Riad al-Shaqfa, to hold a rare press conference in which he denied the accusations. Since then, the Coalition has been expanded to dilute the influence of the Brotherhood and Hitto has stepped down. Qatar, a main supporter of the group, has taken a back seat in favor of Saudi Arabia in dealing with the Syrian opposition.

"Support for the group is not what it used to be," said Ahmad, 32, a resident of Hama. "They've been away for too long and now they try too hard, they buy people," he said, speaking on condition of anonymity for fear of retaliation.

The group is also riddled with infighting among various factions.

Its longtime spokesman, Zuhair Salem, recently resigned reportedly over disagreements with the group's leadership. He refused to comment when contacted by the AP, and al-Bayanouni said his resignation has not been formally accepted.

Mushaweh said the Brotherhood knows fully well that it will not be able to rule alone in the future, nor does it intend to.

"Even if the regime falls, we expect difficult years ahead because the state we will receive will be a heap of stones and humans. Neither the Brotherhood nor anyone else can work alone to rebuild the country," he said.

Lefevre said the Brotherhood still has a long way to go before regaining the full trust of society.

"But because it's a structured and experienced national political force, it will remain one of the powerbrokers in any new Syria and it's a group still worth watching," he said.